Synthesis and characterization of polyethyleneimine-terminated poly(ß-amino esters) conjugated with pullulan for gene delivery.

Cationic polymers endowed with a flexible system for condensing DNA, are regarded as effective materials for gene delivery. The synthesis of poly(ß-amino esters) (pBAEs) based on 1,4-butanediol diacrylate-ethanolamine monomer (1.2:1 molar ratio) and 1,4-butanediol diacrylate-ethylene diamine (1:2 molar ratio) was carried out and modification with 1800 Da polyethyleneimine (PEI) at different weight ratios (3 and 1) as well as conjugation with pullulan in various weight ratios of (0.0625, 0.125, 0.25, and 1) was performed. Gel-retardation assay demonstrated that the synthesized polymers were able to condense DNA at low carrier/plasmid (C/P) ratios. The polyplexes with ratio 3 of PEI (pß1/PEI3) were restricted in all C/P ratios and the polyplexes of pß1/PEI3/pull0.125 were condensed at C/P ratios higher than 0.5. The particle size at C/P was approximately about 200 nm with a positive surface charge. The presence of the pullulan in the structure of the synthesized pBAEs could be effective in reducing toxicity of the base polymer. Highest metabolic activity was dedicated to C/P2 of pß2/PEI3/pull0.125 with 80.6% viability. Furthermore, the most efficient gene reporter delivery was seen at C/P ratio of 6 in pß2/PEI3/pull0.125 nanoparticles. Therefore, pullulan grafting could enhance the cellular response of cells in terms of cytotoxicity and transfection efficiency.

Lactosylated lipid calcium phosphate-based nanoparticles: A promising approach for efficient DNA delivery to hepatocytes.

Objectives: For safe and effective gene therapy, the ability to deliver the therapeutic nucleic acid to the target sites is crucial. In this study, lactosylated lipid phosphate calcium nanoparticles (lac-LCP) were developed for targeted delivery of pDNA to the hepatocyte cells. The lac-LCP formulation contained lactose-modified cholesterol (CHL), a ligand that binds to the asialoglycoprotein receptor (ASGR) expressed on hepatocytes, and polyethyleneimine (PEI) in the core. Materials and Methods: Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR) were used to monitor the chemical modification, and the physicochemical properties of NPs were studied using dynamic light scattering (DLS) and transmission electron microscopy (TEM). To evaluate transfection efficiency, cellular uptake and GFP expression were assessed using fluorescence microscopy and flow cytometry. Results: The results revealed that lactose-targeted particles (lac-LCP) had a significant increase in cellular uptake by hepatocytes. The inclusion of a low molecular weight PEI (1.8 KDa) with a low PEI/pDNA ratio of 1 in the core of LCP, elicited high degrees of GFP protein expression (by 5 and 6-fold), which exhibited significantly higher efficiency than PEI 1.8 KDa and Lipofectamine. Conclusion: The successful functionalization and nuclear delivery of LCP NPs described here indicate its promise as an efficient delivery vector to hepatocyte nuclei.